Mechanical scale



FIG. 1 is a top perspective view of a mechanical scale showing the new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side elevational view thereof;

FIG. 5 is a right side elevational view thereof;

FIG. 6 is a top view thereof;

FIG. 7 is a bottom view thereof; and,

FIG. 8 is a bottom perspective view thereof.

The broken lines illustrate portions of the mechanical scale that form no part of the claimed design. 

CLAIM The ornamental design for a mechanical scale, as shown and described. 